According to founder Robert Redford, the ethos of the Sundance Film Festival can be described in one word: change. “Some people fight and resist it because they are afraid of it,” he noted at the opening-day press conference on Thursday, “others accept it and roll along with it.” Though we're not talking seismic changes, Sundance is certainly a festival that moves with the times, and after the breakout success last year of Beasts Of The Southern Wild – which is following 2009's Precious to the Oscars – this year is definitely attracting interest from an industry looking for fresh new ideas.

They're not being disappointed. Yesterday saw the world premiere of Shane Carruth's Upstream Color, the director's first film since his prize-winning cerebral sci-fi drama Primer in 2004 – and quite possibly the most anticipated movie at Sundance this year. Although the festival attracts hundreds of bona fide movie stars every year – though markedly less stellar, this year's attendees include the likes of Nicole Kidman, Shia LaBeouf, Joseh Gordon-Levitt. Ashton Kutcher and Naomi Watts – Upstream Color is really what the festival is all about: a cool, mystical and at times impenetrable study of human fate. Making Holy Motors look like Nativity 2 by comparison, it is an insanely ambitious piece of work that begins with a woman being tazered and forced to ingest a worm that makes her fall under the spell of a mysterious attacker. This man then hypnotises his victim into handing over all her money, but not before memorising a novel by Henry Thoreau.

The film was well received, but then most films here are, and although the festival got off to a slow start with a couple of decent docs (Who Is Dayani Cristal? and 20 Feet From Stardom) and two OK world dramatic features (Crystal Fairy and May In The Summer), the quality of the films since has been pretty high, For me, the festival really kicked off with Austenland, a divisive chick-lit comedy that stars Keri Russell as a single woman named Jane whose infatuation with the novels of Jane Austen inspire her to sign up for a holiday in a British country theme park modelled on the life and work of the Regency-era authoress. There, Jane teams up with the rich, busty Miss Charming (Jennifer Coolidge), only to realise that her life savings only entitle her to the “copper” edition of the Jane Austen experience while her new but comparatively vulgar friend gets “platinum”.

That the film is divisive is because many were turned off by its exuberant, Comic Strip-style comedy, which tends to focus a lot on Coolidge's bosom and the great lady wailing such bon mots as “GORD SAYVE THA CWEEN!” in a horrible British accent. But there are some smart, literary laughs to be had, and even though Jerusha Hess' film is very, very, silly, it's rare to see a film that so knowingly explores the reality of many women's secret fantasies and desires. It's even more rare, however, to see women's fantasies and desires explored as boldly as they are in Anne Fontaine's Two Mothers, which stars Naomi Watts and Robin Wright as two middle-aged best friends who embark on affairs with each other's sons. The absurdity of the set-up put many viewers off, but although there is definitely some unintentional humour in some of the dialogue (“We've crossed a line!” observes a straight-faced Watts), there's also a lot of sexual tension and atmosphere to relish here, and the film, boosted by two great leads, definitely makes a provocative impression.

Perhaps the biggest surprise for me so far has been Daniel Radcliffe's performance as Beat poet Allen Ginsberg in Kill Your Darlings, the true story of a scandalous wartime murder in uptown Manhattan. John Krokidas's film tells the story through the eyes of the young Ginsberg, who meets Lucien Carr (Dane DeHaan) in his first days at university and is seduced into a world of jazz, drugs and literary hedonism. Unworldly and inexperienced, Ginsberg is initially confused by his attraction to Carr, but the shadowy presence of David Kammerer (Michael C Hall), a somewhat creepy older man who follows Carr everywhere, alerts Ginsberg to his own blossoming homosexuality. The fact that Carr kills Kammerer is no spoiler, since this is how the movie starts, but what is surprising is how well Radcliffe plays out Ginberg's crucial early life journey, transitioning from a wide-eyed ingenue to a radicalised bohemian whose poetry would change the course of literary history.

Jumping forward a few days, fellow Harry Potter alumnus Rupert Grint plays a small but perfectly formed part in Fredrik Bond's excellent and at times uproarious The Necessary Death Of Charlie Countryman, in which the young Chicagoan of the title, played by Shia LaBeouf, takes a trip to Bucharest to recover from the death of his mother. It takes a while to heat up, but when it does, Bond's film is a great, sleazy crime caper, with Countryman falling for Romanian gangster's moll Gabrielle (Evan Rachel Wood), ex-wife of vicious gangster Nigel (Mads Mikkelsen). Unfolding backwards, the film starts with our bloodied, weeping hero hanging from a rope and about to be shot, and Matt Drake's script has a lot of fun explaining how Countryman got there. Bond's use of music is excellent and his vision of eastern Europe both hellish and magical; that Grint plays a wannabe porn star named Boris Pecker is just one of the many delights of a gripping, violent film that owes an unabashed debt to the Tarantino-penned love-in-low-places story True Romance.

Speaking of porn, who would have thought that Joseph Gordon-Levitt's directing debut Don Jon's Addiction would be so near the knuckle (pun intended)? Gordon-Levitt stars as Jon, an Italian-American jersey boy who pumps his muscles, pimps his ride, and keeps his crib squeaky-clean for the endless procession of women he takes back to his pristine apartment. When Jon meets the ten-out-of-ten club girl Barbara (Scarlett Johansson), he falls in love. But Jon has a secret: though he every inch a ladies man, he is also an internet porn addict, scouring the internet for hardcore and softcore images, since he prefers the fantasy version of sex to its awkward, grunting reality.

If you still haven't quite got your head round Gordon-Levitt's recent ascension to leading-man status, this film will blow your mind, not only showing the still-boyish actor pumped up to eye-popping proportions, but displaying a sexual frankness one rarely sees even in independent cinema these days. And then there's the sight of Johansson as we've never seen her before, flaunting her curves, chomping on gum and yakking away in a Noo Joisey accent – a killer combo that leads us to the film's subtle about-turn. That Jon mends his ways is perhaps to be expected, nevertheless, Gordon-Levitt does it with style and energy and a very human conclusion (hint: it involves Julianne Moore), that combined to create the opening weekend highpoint of a very promising festival.